Fifty years ago, cannabis was known as the drug most emblematic of counterculture. Today, many people promote it as a fount of treatments for almost any ailment imaginable. This immense about-turn is reflected in changes in legal regimes: medicinal use of cannabis is now permitted in many countries, and some also allow the drug to be used recreationally. The times, they have a-changed.

No aspect of the cannabis journey better exemplifies its current status than the fortunes of cannabidiol. This cannabis extract has received regulatory approval in the United States for use in treating certain rare forms of childhood epilepsy. But cannabidiol is also often promoted, with little supporting evidence, as a general health elixir.

Numerous clinical trials that are investigating potential medical benefits of the many chemical components of cannabis are painting a promising picture, albeit one that is blurred by a lack of clarity over how the plant’s compounds interact. Researchers are also looking into the effects of combining cannabis consumption with exercise, after decades of positive anecdotal reports from athletes. But evidence of ill effects associated with cannabis use, including worrying correlations with mental illness, must be weighed against the drug’s possible medical value.

Legalization brings the benefits and burdens of operating a regulated industry. Cannabis growers are paying more heed to quality control and the environmental impact of cultivation. And genetic engineering is enabling researchers to optimize the cannabis plant for the mass production of pharmaceutical drugs. Meanwhile, policymakers who are seeking to integrate cannabis into society might need to rethink their approach.